Why use the Multivariate Sensitivity Study?

Cover a large solution space

Analyze whole solution space of flowsheets even with convergence problems with brute force to save time.

Find Pareto-Optimal Solutions

Visualize solution spaces for multi-objective optimization problems with pareto optimal points to support decision making.

Apply Constraints with Filters

Discover the correlations of design variables and dependent variables in response to your process and product specifications.

Use Case 1 - Optimization of a Batch Distillation for Solvent Recovery

Problem

Objectives

  • Minimize energy demand
  • Minimize operation time
  • Maximize product yield

Challenges

  • Infeasible design specifications may cause convergence problems
  • Product concentration as a constraint
  • Product specifications must be given indirectly as design specifications due to the accumulated product
  • Correlation of design and state variables are not obvious

Solution

Set-Up of the Multivariate Sensitivity Study

  • Five design variables
  • Equidistant grid (per variable)
  • 78.125 flowsheet runs (mass transfer batch column simulation)
  • Calculation time on 6 machines*: approx. 3 days

Results

Increase efficiency of Solvent Recovery

  • 74% energy saving
  • 4.5 h reduction in operation time
  • 7% increase in product yield

Use Case 2 - Distillation of an Ethanol-Water Mixture

Problem

Objectives

  • Maximize product yield
  • Minimize energy demand

Challenges

  • Product concentration as a constraint

 

 

Solution

Set-Up of the Multivariate Sensitivity Study

  • Two design variables
  • Equidistant grid (per variable)
  • 9.550 flowsheet runs (SCDS distilation simulation)
  • Calculation time on 7 machines*: approx. 2 hours

Results

Understand the correlations between variables

  • Use the sliders on the report below to apply limitations
  • Observe the relationship between variables.
  • Check the sensitivities by varying:
    • EtOH fraction
    • Reboiler duty
    • Distillate rate

*Our cluster is 5 machines with Intel dual core 3.06 GHz and 4GB RAM and 2 machines with Intel core 2 duo 2.93 GHz and 4 GB RAM.
Both processors have been produced until 2007 and 2008.